Ubiquiti Networks RocketDis LW - Manual (Page 5)

2. The Dish Reflector and Antenna Feed are keyed so the
Antenna Feed can only be installed in a single orientation.
Follow these steps:
a. Remove the knob from the Antenna Feed.
b. Line up the alignment pins of the Antenna Feed with
the alignment holes of the Dish Reflector and Mounting
Bracket.
Note: Ensure that the straight edge of the
Antenna Feed end (shown below) and arrow on
the Antenna Feed cap are pointing straight up.
c. Insert the Antenna Feed.